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 Many people have some misconceptions about energy. Here are some common myths…and real facts!
  •  MYTH: If I leave my computer on without using it, the screen saver will come on and that uses almost no energy at all.
  • FACT: This is NOT true! The screen saver does absolutely NOTHING to save energy. Please set your computer to “sleep” instead (see “So what can I do?” section).
  • MYTH: Turning off my computer is bad for my computer. 
  • FACT:  Modern hard disks are not affected by frequent shut-downs and equipment my actually last longer because mechanical wear and heat stress are reduced.
One computer left on 24 hours a day will cost $115 - $160 in electricity costs a year and dump 1,500 pounds of CO2 into the atmosphere.

A tree absorbs between 3 to 15 pounds of CO2 each year.  That means that 100 to 500 trees would be needed to offset the yearly emissions of one computer left on all the time.
  • MYTH: Fluorescent lights consume a lot of energy during startup, so they should be left on as much as possible and avoid frequent switching.
  • FACT: Whereas this was true when fluorescents first became popular (1940s), the effect of frequent switching on modern lamp life is not as detrimental. In fact, according to the Naval Civil Engineering Laboratory, the lights need to be off for just one second before it compensates for that surge of starting current!

  • MYTH: The room will get cooler faster if the thermostat is set lower (50 to 60 degrees)
  • FACT: The room will cool down just as fast if the thermostat is set on 72 degrees. If the thermostat is set too low, the unit will freeze up and will not cool at all. 

  • MYTH: The door should be left open while the heat or air conditioning is on, to help circulate the required amount of fresh outside air.
  • FACT: Most heating and air conditioning units in the District are designed to pull the required amount of outside air into the classroom, and circulate all the air through a filter. This will provide clean, fresh and conditioned air all the time. The door should be kept closed to allow this system to work properly, and prevent damage to the equipment due to excessive wear.